Fluid pump or motor.



K. KEEER,

FLUID PUMP 0R MQEGR.

APPLloATmN FILED JAN, 9. 1911.

Patented July 14,1914,

.N .kwak

` FLUID rumana Moron.

To all whom t may concern eration of the vteeth thereof.

' tally disposed inlet-1:

Be it known that I, KARL Kram, a citi.- zen of the. United States,Aresiding at Cincinnati, in the county" of Hamilton and .State of Ohio,have invented a 'new and '-'useful ImprovementY in Fluid Pumps orMotors, ofwhich the following is a specification.

My invention relates tary pumps or motors, provide a device of this todouble-piston roand the Objectis to character of simple constructionthat will be highly efficient,

and steady and quiet in its o ratlon.

My invention consists in t e parts and details of construction andarrangement of parts,-as will be hereinafter more fully described andclaimed.y

In the drawings: 'Figure 1c is a vertical section taken through themiddle of apumplongitudinally of .the inlet andout-let. Fig.

2 is a vertical cross section taken throughv the middle of thepumplongitudinally of theshafts. Fig. Sis a detailed side elevat-ionofi-the rotors or pistons of the pump.

Fig.- 4- isa detailedperspective-View of one of the ends of the casing,better illustrating its inside formation. Fig. 5 is a diagrammatic viewto illustrate vthe operation of Vthe teeth of the rotors or pistons.Fig. 6 is a detailed perspective view'of 4a part of one of thev pistonsto further' illustrate theop- The-casing 1 of the-pump'hasa4 horizonandafsimilarl'ydis posed outlet 1 'on'ther'opposit'e side'from lthe inlet,andthe ends vlian'd 1b, of the cas'-v ing support the, rotors or pistons2 and 2a l with their centers tactis made -Outlbfa-'S will hereinafterbe. 'moreifllly set forth.' Except Awhere' theyv 'enter- A. the inletand outlet passages,

theinner pistonsrunning vinthe' directions lndicated '55 b the arrows,the liquid vl'enteringat the in.

or axes equidistant above and below, respectively, .the center line ofthe inlet: and outlet. yThese -rotors'or p15-P tons 2 and .2 havevhelicalteeth` 2. and 2a" which mesh together-between theinlety 1 andthe outlet-1 and the teeth .are so ar-y ranged,vand -of such .proportionand osch numberthat a substantially fluid-tight con'` hereby betweensaid inlet and.

thel'pistons- 2 and@ are inclose'd by the walls ofthe. casing 1 ,so thatthe teeth 2- andfgl"Larefcloseiy adjacent for e walls, and lthe concavesides: of y,th

let 1f will .be carried around inthe spaces between the teethto theoutlet 1, where it Specification of Letters Patent. ,Application filedJanuary 9, 1911. Serial No. 601,599.

is forced from" between `said -spaces by the Patented July 14,1914. 1 I

intermeshing of /tlieteeth 2 and 2a of the l pistons. A by-pass 3 leadsfrom' the. outlet 1. in-

. teriorly of the wallgofthe casing 1, `over the upper pistonv 2 anddownto the inlet 1, and

is closed by the valve 3 located verticallyI above the pistons, which isunseated upward, and normally held'y down by a, spring 3* adJusted by 4ascrew v39;' thusthis valve 3a may be adjustedv to maintain: any ydesired pressure at' the )outlet 1, and tol allow the excessffluidto,;pass back'to the inlet through the luy-pass'l.'

The two rotors yorjgstonsQ and 2a preferably have their teethk designedtheoreti# cally correct sothat'they constitute. a pair of intermeshingears, and the upper -piston or gear 2 is a apted to drive the lowerpiston or rear 2". Accordingly', itis possible to avoid .the use ofl anobjectionable number of stuiing boxes or glands around the shzuftsV ofthe pistons vor gears. .As ill'u`strated,`it is`-l I necessary to have aglandaround the driving 2 only,.the 'stud 2c which supports said gear 2being rigidly upper gear 2 has a central bore, turn' loosely lon', andtheremaining part `of sald bore receives -the inner end of ing shaft 2",which has a-key 21.rigidl .securing it to the gear. 2. The part o theshaft'2b of 'the upper piston or gear mounted inthe casing, as 1s 'yalso the shaft/2'd of the lower gear 2a. 'The into .part ofV whicextends' the 'studv 2c `for said gear to driving shaft 12?" 'outside ofthe'casing may be provided with an driving the pump, w necessary'vgtoherein" The lower ,crear 2" t`urns loosely yon'th'e shaftf2df I' *ilsuitable means *for* 'lift 'icli'it vis not deemed illustrate ordescribe."

1 liis- Waite aangaande of thejcasing have extensions 2', .to receive av d surround the ends of the'shaftl", laiid'f-th endl? has 4 similarextension 2?. whichrece'ives and s urroundsltheend'of'the'f'stud 2F.g'l`hebear1ng"' 2 for 'the'shaft 2h basa". 'stuiilng box or gland ij 1-2? around fthe sh 'ft -arjic'ifbetweenthis gland andtheige'ar 2 thereisan 'annular -recess 2" i 5 -10 inunieate's,controlled`by aplugQf.Leading 'frolnv the, annular recess 52"1 interiorly pf v lubricant andact as a'reservoir .therefor infside the gear 2. i Thestud l2c has aspiral.`

groove 2g on its convex surface that communicates between the space 2gand an interior passage 2g. inside the stud 2c that leads from the endof said spiral groove 25, inside the gear 2, toI the end of the stud 2inside the extension 2', which is provided with an outlet controlled bya plug 2h. The shaft 2d has an linterior passage 2d leading from one endto the inside of the gear 2, and there communicates with one end of thespiral groove 2k, the other end of which communicates with anotherinteriorpassage 21, in the shaft l2, leading to the other end of theshaft inside of the other extension 2d', one of said extensions beingprovided with a grease cup 2m controlled by a plug 2u, and the otherextension having an outlet controlled bythe plug 2. It will. thereforebe seen that the lubricant can be supplied to.

the gears 2 and 2a by opening the plugs 2f;

and 2m', respectively, w ile that which has been used may be allowed toescape by opening' the plugs 2h and 2, respectively. Vl these plugs areclosed and the stuf'ing box 2e is roperly packed, no lubricant canescape rom the pump to the outside. For confining the lubricant aroundthe shafts, the gears are provided on their ends with annular ackingrings or gaskets 2P, which bear against the innersides of the ends l andlb of the casing, so that the lubricant can' not mingle with the fluidbeing moved by the pump.

lt will be noted that the valve 3 in the bypass 3 has a conical seat3a', but that the openin below this seat has parallel lsides while t evalve 3a is shaped accordingly, so that it may have considerablevertical movement before the valve will be permitted to vibrate, as itwould if only held in alinement by its spring 3b. Also, this valve 3ahas an upper cylindrical extension 3a that fits closely in a cylinder 3Wthat forms part of the valve casing; with the plug 3', which carriesthescrew 3", screwed into the upper end of this cylinder 38', thecylindrical extension 3a of the valve 3 confines a certain amount of airinside the cylinder 3a, so that the arrangement performs the function ofa'dash-pot with a steadying effect on the operation of the pump.

4ingl The pressure gage may be applied to the pump in the threadedopening 3 leading to the by ass 3, and the lower part of the casas anopening 1. in which a drain cock Imay be applied to the pump. v

' The teeth -2 and 2a ofthe pistons or gears 2 and 2 respectively, are,onY each gear, inversely directed from the ends of the gear toward themiddle thereof, meeting in the mid-l dle at an angle sothat they are ofwhat is known as herring bone formation, and of course, as is necessaryin helical gears, the,

heny

the teeth be theoretically correct; it is necessary that there always beteeth of the respective' gears making continuous contact from end to endof the gears, so as to maintain the substantially fluid-restrictingmeans between the inlet and outlet, the absence of which so seriouslylowers the eiliciency. W'ith the use of the helical gear teeth, thiscontinuous line of contact from end to end o the gear is of shorterduration than with simple spur gears, and it is necessary to provide theteeth 'in such a manner that before any two teeth begin to recede fromeach other near one end of the gear, and thus destroy the continuousline ofV contact, the next two teeth will have .completed theircontinuous line of contact from end to end of the gear. A

- The above will be understood upon inspection of Figs. 5 and 6 of thedrawing.

In 5 the tooth A of one gear and` the tooth A of the other gear'aremaling contact at a. Now, let it be understood that each half-length ofa tooth, from the angle in the middle of the herring-bone gear to eitherend, is to be considered as a complete tooth for the purpose of thefollowing explanation. Also let it be assumed, for instance, that. asillustrated in Fig. 3, the pitch of the helical teeth is such that atooth advances a distance equal to the circular pitch of the gear.rlhus, the other end o1 the tooth A will be coincident with this end ofthe tooth B; and the point of contact at that other end will becoincident with the point of contact seen at b between the teeth B and Bin Fig..5, which, of course, shows this end only. The line of contactmade by the tooth A alongthe side ofthe tooth A will be projected alongthe line as seen in Figs. 5 and 6.

The same relation exists between the teeth B and B, which, as seen inFig. 5, make contact at b at their near ends; at their in theiradvanced'regions, coincident with the brea the continuity of theirlineof contact ,int c, the teeth B and Bf are about to lFrom the aboveitwill' be understood that, u

c', but the teeth'A and A are completing their continuous line ofcontact y at a, where the teeth end at the sides of the gears, as aboveexplained. Thus, the' teeth A and A are complementary tact.

Ateeth is afforded in tion of the fluid from the spaces between thelonly being necessary t in the middle of the gear,

.Consideration of the above circumstances w1ll make it apparent thatsuch operatic-n of `the teeth as above described is dependent upon therelation of the length of the gear to the helical pitch and the circularpitch of the teeth. Forexample, with such a rotor or piston of lengthapproximating its diameter, it is necessary to have from 20 to 30 teeththereon, each advancing around the piston a distance about equal to thecircular pitch of the teeth. By thus assuring a constant closed jointbetween the intermeshing teeth, the helical teeth aremade just asefficient as any other form of impeller, with ref' spect to leakage ofthe pump, andv the full advantage attained by the use of lhelicaltheoperation of the pump. This advantage consists in the ejecteeth, bythe intermeshing of the teeth, in direction toward the end of the gear.By providingy the teeth of each gear pitched in both directions andmeet-ing at yan angle in the middle of the gear, or of herring boneformations the fluid thus passes tofboth ends of the gears and escapes ito the outlet 1` through the recesses 2f in the inner sides of the endsla and l" ofthe casing. 1t will of course be understood that. some ofthe Huid will be displaced over the tops of the teeth when theyintermesh, but the endwise means of escape afforded for the Huid greatlyincreases the smoothness of operation of the pump, and practicallyeliminates all lvibration, which has been a very objectionable featurein pumps of this character heretofore produced, in pumping liquids.

From the foregoing descri tion it will be 'understood that thecontinuity lof fluid reous contact between the lrespect-ive teeth to theangle ofhelical 'advance of the teeth; and this advantage is notdependent upon coincidence of overlap ing tooth-ends, vit

liat the helical ad- Vance be less than the angle of rotation duringwhich the respective gears have the con 'nuous contact-.I advantage isattained in connection withthis continuity ofV iuid restricting contact4by making the overlapping tooth-ends coincii dent as shown. By thushavlng 'the end of a tooth at one end of the gear, or at the anglecoincidentwith the beginning of a following tooth, at the other end, thefull advantageof the helical to the teeth- B and B in maintainingconstant huid-restricting con-f any L tion in these regions 'teeth wherethey However, an importantl gear inproducing steady delivery of fluidwithout pulsation is attained; for without such coincidence the gear hascharacter of a .plain spur gear with teeth running parallel to the axis.lVith lSuch a plain spur gear, `or with a helical or herring-bone gearwithout the coincidence of tooth-ends above alluded to, there is avariation of condition in the region where the teeth emerge from theinclosing concave casing walls. With the. plain spurgear, at one instanta complete tooth-top will bel presented, and at the next inst-ant acomplete interdental space will be kind lof helical gear not having thetooth-ends coincident, -t-hese tops and spaces will be varyinglypresented with less degree of completeness across the gear, but yet witha large degree of irregularity of condition in these regions. With thetooth-ends coincident, there will beno instant when there is a completetooth-top presented or when there is a complete interdental spacepresented, while,`in addition, the proportion of top and space-presented will always be the same, and the conditions in this regionwill be uniform; so that by this means not only is the advantage gear,but this advantage of the helical or herring-bone gear is completelyattained.

ASince freely open interdental space in this region permits free escapeof fluid, and a tooth-top in this region prevents escape', it will beseen that acohstant proportion o these two will result inl eliminationof alternate increase and decrease, or pulsation, of

delivered fiuid.. Such uniformity of condiwhere the fluid escapesv frombetween theteeth will, however, be of .little significance without thecontinuity of iiuid restricting contact between Ethe interm'eshingteeth,because leakage back between the teeth, in addition to being asource of waste, is also a cause .of irregularity of delivery of fluidand also causes pulsations wherepermitted. 'lt is, therefore, by themore of the presented; and with attained over the plain spur combinationof these provisions that my obvject is attained most completely. U Whilethe above provisions eliminate pul-- sation in the deliverycf a pumpftheopera.- tion of a. motor constructed as above described will besteadier, on account of, the uniform rate of inflow of fluid between theenter behind the concave walls of the casing, and because of the elimi.nation of leakage between the teeth of the two gears where theyintermesh.

. Having fully described my 1nvention,what` 1 claim as new and desire tosecure by Letters Patent is? 1;V In a pump or Iimotor pistonsconsistingl of intermeshed helical gears, respective teeth of which havecontinuous contact from end to end during rotation thereof through avancing helically thereon, vrespective teeth of which have continuouscontact from end to end of the helical advance of the respective teethduring rotation of each gear through a certain angle, and said helicaladvance of each tooth being through an angle not eX- ceeding said angleof rotation. 3. In a pump or motor having an inlet and an outlet,pistons consisting ot' intermeshed gears, each with .teeth advancinghelicallyv thereon, respect-ive teeth of which have continuous contactfrom end to end of the helical advance of the respective teethy duringrotation of each gear through a certain angle and said helical advanceof 4each tooth beirfig throughv an angle not exceeding said angle ofrotation, the outlet mea-ns having communication -at the ends of thegears with the spaces between the teeth Where lthe gears mesh.

4t. ln a pump or motor pistons consisting vof intermeshed gears, eachhaving inversely arranged helical teeth forming angles mid- Way of thelength of the gear, the respective teeth of said gears having continuouscontact from end to end during revolution thereof through a certainangle, and the angle of advance of each tooth, from the end of the gearto its angle midvvayof the length of the gear, being not in excess ofthe aforementioned angle.

5. in a pump or motor, pistons consisting of intern'leshed gears, eachwith teeth advancing helically thereon inversely and forming anglesintermediate of the length of the1 gear, respective teethY of the gearshaving continuous contact freni end to end of' the helical advance of,the respective teeth during rotation of each gear through a certainangle, and said helical advance of each tooth being through an angleynot eX- ceeding said angle of rotation. f 6. ln a pump or motor havinga casing with an inlet and an outlet, pistons therein consisting ofintermeshed gears, each With teeth advancing helicallythereon inverselyand forming angles intermediate of the length of the gear, .therespective teeth of i said gears havlng continuous contact from end toend of the helical advance of the respective teeth during rotation ofeach gear through a certain angle, and saidhelical advance of each toothbeing through an angle not exceeding said angle of rotation, and thecasing adjacent to the' ends of the gears having spaces :communicatingWith the spaces 7. ln a pump or `motor, pistons consisting ofintermeshed gears, each With teeth advancing helically thereon,respective teeth of which have continuous contact from end to end of thehelical advance of the respective teeth during rotation of each gearthrougha certain angle, lsaid helical advance ofeach between the teethWhere-the gears mesh, and Iwith said outlet.

tooth being through an angle not exceeding said angle of rotation, andeach of the teeth being,.at'the end of its helical advance, coin-.cident with the beginning of helical advance of another tooth ontherespective gear.

8.V ln a pump or motor, pistons consisting of intermeshed gears, eachwith teeth fadvancing helically thereon inversely and forming anglesintermediate of the length of the gear, respective teeth ot uthe gearshaving continuousicontact fromend to end ofthe helicaladvance of therespective teeth during rotation of each gear through a certain angle,said helical advance of each tooth `being through an anglenot exceedingsaid angle of rotation, and each tooth, Where its helical advance endsat the angle intermediate of the length ot' the gear, being coincidentwith the beginning of the helical advance of other inversely helicallyadvancing teeth on the gear.v l

ln testimony whereof l have signed my name to this specification in thepresence of two subscribing Witnesses, this 5th day of January, 1911. 1

' Kann Kieran.

It is hereby certified that in Letterslatent No. 1,103,053, granted July14, 191.4,

upon the application of Karl Kiefer, Fluid Pumps or Motors," errors`appear in the printed specitieation requiring co1'- reotion as follows:Page 9i, line 115, for the reference-letter au read y; same page,

line 125, for the reference-letter y read and that,l the eaifi LettersPatent should be read with these corrections therein that the same mayconform to the record of the ease in the Patent Oiice. i

Signed. and sealed thisQOth day of October, A. D., 1914.

J. T. NEWTON [SEAL] i u Acting Commissioner of Patents.

of Cincinnati, Ohio, for an improvement in

